Self-locking latch



Jan. 7, 1969 B. P. DUNCKEL SELF-LOCKING LATCH Sheet Filed Oct. 22, 1965INVENTOR. BRUCE PATTEN DUNCKEL BY I ATTORNEYS Jan. 7, 1969 B. P. DUNCKEL3,420,995

SELF-LOCKING LATCH Filed Oct. 22, 1965 Sheet 2 of 2 ATTORNEYS UnitedStates Patent 3,420,995 SELF-LOCKING LATCH Bruce Patten Dunckel, StoneMountain, Ga., assignor, by mesne assignments, to Lithonia Lighting,Inc., Atlanta,

Filed Oct. 22, 1965, Ser. No. 502,038 US. Cl. 240-78 Int. Cl. F21s 1/06;Ec 5/00 6 Claims ABSTRACT OF THE DISCLOSURE This invention relates to aself-locking latch, and more particularly to a self-locking latch of thetype adapted to be used to insert a reflector of a lighting fixture intoa mounting frame therefor that is positioned inside the ceiling of abuilding.

Recently it has become desirable to construct homes and buildings withacoustical tile ceilings, or ceiling material similar thereto, portionsof which are easily removed or replaceable. The manner in whichacoustical tile is attached to a ceiling is generally that support meansare suspended from the ceiling or adjacent walls and run across theceiling, and the acoustical tile is attached to the support means. Thismanner of construction creates a space between the original ceiling ofthe building and the acoustical tile which can be utilized, if desired,to run heat ducts, electrical wires, plumbing, and other items necessaryto the construction of the building.

Because of the space created between the original ceiling of a buildingand an acoustical tile ceiling, it has become convenient to installceiling light fixtures in the acoustical tile ceiling so that lightfixtures are recessed into the acoustical tile ceiling and only a smallportion of the fixture extends below the acoustical tile ceiling level.This method of installation is desirable since the light fixture is notnoticeable when it is not illuminated, and it does not hang down adistance below the acoustical tile ceiling so that it might interferewith other furniture or fixtures in the room, or hang down low enough sothat a person walking through the room would inadvertently bump into thedangling fixture. Of course, the lower the ceiling, the more desirableit is to have the light fixture recessed into the ceiling.

In the past, fixtures suitable 'for mounting in acoustical tile ceilingshave been available, but have been troublesome and annoying to install.Some of these fixtures must be installed when the ceiling is beinginstalled, and the elements utilized in positioning the fixture in theceiling are awkward and diflicult to manipulate, and are constructed ina manner so that the portion of the fixture extending into the roombelow the ceiling is not easily aligned and leveled with the surface ofthe ceiling.

Accordingly, the present invention relates to a selflocking latch whichis adapted to be connected to the reflector of a lighting fixture andengage a mounting frame mounted between the original ceiling and anacoustical tile ceiling so that the mounting frame can be positionedinside the acoustical tile ceiling, connected to a junction box, and thereflector can be inserted into the mounting frame, through theacoustical tile ceiling from below the 3,420,995 Patented Jan. 7, 1969"ice ceiling, so that the self-locking latch locks the reflector to themounting frame. With this arrangement it can be seen that the junctionbox, its associated wiring, and the mounting frame can be positionedbetween the acoustical tile ceiling and the original ceiling of thebuilding while the acoustical tile ceiling is being constructed, andafter the completion of the acoustical tile ceiling the reflector can beinserted through the hole in the ceiling, engaging the mounting frame, alight bulb screwed into the electrical connection, and the appropriateglass placed over the bulb.

Accordingly, it is an object of this invention to provide self-lockinglatch for connecting a reflector of a light fixture to its mountingframe whereby the reflector can be inserted varying distances into themounting frame.

Another object of this invention is to provide a selflocking latchadapted to be connected to the reflector of a lighting fixture, wherebythe reflector can be inserted into a mounting frame therefor a varyingdistance, and latch can be adjusted so that the mounting frame and thereflector are adjusted toward each other so that the refiecor can beperfectly aligned with its surroundings.

Another object of this invention is to provide a lighting fixture of thetype recessed into the ceiling of a building, wherein the fixture iseasily assembled and adjusted.

Another object of this invention is to provide a latching means adaptedto lock an element to a mounting frame, wherein the mounting frame ispositioned interiorly of the surface of the ceiling, wall or floor, andthe element is adapted to project slightly outwardly of the ceiling,wall or floor.

Another object of this invention is to provide a selflocking latchingmeans that is easily manipulated adjustable, and well designed to meetthe demands of economic manufacture.

Other objects, features and advantages of the present invention willbecome apparent upon reading the following specification, taken inconjunction with the accompanying drawing, in which:

FIG. 1 is a perspective view of an assembled light fixture.

FIG. 2 is a perspective view ofan assembled light fixture, with partsbroken away to show the interior.

FIG. 3 is an exploded perspective view of a light fixture, showing itsmanner of assembly.

FIG. 4 is an exploded perspective view of a self-locking adjustablelatch.

FIG. 5 is a side elevational view, partially in cross section, of theself-locking adjustable latch taken along lines 55 of FIG. 4.

FIG. 6 is a side elevational view of the self-locking adjustable latch,smilar to FIG. 5, but showing the latch in its locked position.

Referring more particularly to the drawings, in which like numeralsindicate like parts throughout several views, FIG. 1 shows an assembledlight fixture 10 having a mounting frame 11, a junction box 12,reflector 14, and door 15. As shown in FIGURE 3, the mounting frame 11is generally rectangular in shape and has a vertical side wall portion13 and an inwardly projecting rim 17. The hanger bars 16 are slideablyattached to opposite sides of the mounting frame 11 on its vertical sidewall portion by means of the tabs 18. The hanger bars 16 are slid alongthe edge of the mounting frame 11, between the mounting frame and thetabs 18, so that the tabs slideably receive the hanger bars 16. Sincethe hanger bars 16 are slid into the tabs 18 from opposite directions,they can be positioned so that their ends 19 do not project beyond theside of the mounting frame perpendicular to the side to which they areattached. Of course, the hanger bars can be slid outwardly of themounting frame, as shown in 3 FIGS. l3, and still be securely fastenedto the mounting frame because of the close spacing of the tabs 18.

The junction box assembly 12 comprises a junction box 20, a junction boxsupport 21, and an electric light bulb socket 22, and a socket support24. The junction box comprises doors and 26 which are connected to thebox 20 by fitting tabs 28 and 29 into the cut-out portions 30 and 31 ofthe box 28, and attaching screws 34 through hole 32 to the box 20 at 35(not shown for the door 26). The socket support 24 comprises a runner 36adapted to be positioned parallel to the junction box support 21 andslideably held thereby in the tabs 38. The runner 36 terminates in a tab39 disposed vertically to the runner 36, and the junction box door 26 isarranged so that it closes over the runner 36 so that the tab 39 ispositioned inside the junction box 20. The socket support 24 has anangle support portion 40 positioned above the light socket 22, which isadapted to hold the light socket away from the reflector 14.

With this arrangement, it can be seen that the electrician, uponinstalling the light fixture, can connect the building wiring to thewiring of the light socket 22, connect the light socket 22 and itssupport 24 to the junction box support 21, position the door 26 on thejunction box which would lock the light socket 22 to the junction box,and close the rear of the junction box 20 with its door 25.

The support 21 of the junction box assembly 12 has a connecting piece 41disposed perpendicular thereto. The connecting piece 41 is arranged sothat it fits through an elongated aperture 42 and is engaged by the tabs44 in the mounting frame 11. An aperture 42 and tabs 44 are located onopposite sides of the mounting frame 11, adjacent the hanger bars 16 sothat the junction box assembly can be mounted on either side of themounting frame 11.

A reflector 14 has a main body portion 45 and a flanged portion 46. Themain body portion 45 is dimensioned slightly smaller than the interiorperimeter of the mounting frame 11, while the flanged portion 46 isdimensioned so that its perimeter is substantially larger than theperimeter of the mounting frame 11. Since the mounting frame 11comprises a generally vertical side wall portion 13 and an inwardlyprojecting rim 17, the interior perimeter of the mounting frame isdefined by the interior perimeter of the inwardly projecting rim 17, andthe exterior perimeter is defined by the outer surface of the verticalside wall portion 13. Thus, the main body portion 45 of the reflector 14is smaller than the inner perimeter of the inwardly projecting rim 17,while the exterior perimeter of the flange portion 46 of the reflectoris larger than the exterior perimeter of the vertical portion of themounting frame. With this arrangement, it can be seen that the reflectorcan he slipped into the mounting frame so that the main body portionextends above the mounting frame, while the flanged portion 46 limitsthe movement of the reflector 14 through the mounting frame 11.

The reflector 14 has an aperture 48 in its main body portion that issized to receive the light socket 22 of the junction box assembly. Theflanged portion 46 of the reflector 14 has a stepped portion 49 and anoutwardly extending flange 50. The stepped portion 49 has T-shapedapertures 51 along oneside thereof and a bendable tab (not shown) on theside opposite to the side defining the T-shaped apertures. The door 15comprises a lens 52 and a frame 54. The frame 54 receives the lens 52and firmly holds it in place by means of the continuousinwardly-extending flange 55 disposed on one side of the lens and theplurality of tabs 56 disposed around the frame on the other side of thelens. The frame 54 also has a pair of outwardly-extending T-shaped tabs58 attached to one side thereof and spaced apart a distance equal to thespacing between the T-shaped apertures 51. The door 15 is attached tothe reflector 14 by slipping the T-shaped tabs 58 into the T-shapedapertures 51, and pivoting the 75 door up parallel to the face of thereflector so that it fits snugly within the stepped portion 49 of theflanged portion 46 of the reflector, whereupon the bendable tab (notshown) on the side of the reflector opposite to the T- shaped apertures51 receives the door and firmly holds it in this position.

The reflector 14 has a pair of latches 60 mounted in its main bodyportion, on opposite sides thereof. As is shown in FIGS. 4-6, thelatches 60 comprise generally a mounting piece 61 and a latching element62. The mounting piece 61 has a rectangular base portion 64, supporttabs 65, attaching flange 66 and an adjusting flange 68. The reflector14 defines rectangular holes 69 on opposite sides thereof of sizesslightly larger than the rectangular base portion 64 of the latches 60.The latches 60 are connected to the reflector 14 by positioning eachlatch inside the main body portion 45, positioning the tab 65a outwardlyof the main body portion 45, while keeping the tab 65b inwardly of themain body portion 45, and Sliding the latch upwardly so that thesupporting tabs 65 grip the main body portion 45 of the reflector 14.The rectangular base portion 64 is then pivoted so that it is containedwithin the rectangular hole 69 and the attaching flange 66 comes to restagainst the side of the main body portion 45 of the reflector. Theattaching flange is then connected to the main body portion 45 byinserting appropriate rivets or screws through the mating apertures 70and 71 of the attaching flange 66 and the main body portion of 45,respectively.

A latching element 62 is positioned adjacent the rectangular baseportion 64 of the latch 60. The latching element 62 comprises a bodyportion 72, wing pieces 74 disposed perpendicular to the body portion 72and along opposite edges thereof, an adjusting flange 75 attached to thebottom edge of the body portion 72, and a finger catch 76 disposedperpendicular to the body portion 72 and along the edge thereof oppositefrom the adjusting flange 75. The body portion 72 is centrally aperturedwith an elongate aperture 78 disposed horizontal to the wing pieces 74.

A pin 80 having a cap 81 and a shank 82 is adapted to be insertedthrough the elongated aperture 78. The rectangular base portion 64 iscentrally apertured at 84 and a coiled spring 85 and an annular washer86, of conventional design, are slipped over the shank 82 of the pin 80,the shank inserted through the elongate aperture 78, and through theaperture 84 of the rectangular base portion 64, and the pin securelyattached to the rectagular base portion, as by brading or screwconnection. Of course, connecting the pin 80 to the mounting piece 61 inthis fashion causes the spring 85 to be compressed between the cap 81and the mounting piece 61. The washer 86 and latching element 62 arebiased toward the mounting piece 61 so that the wing pieces 74 of thelatching element 62 project outwardly of the reflector 14, between therectangular base portion 64 of the mounting piece 61 and the edges ofthe aperture 69 of the reflector 14.

The adjusting flange 68 of the mounting piece 61 and the adjustingflange 75 of the latching element 62 are centrally apertured at 88 and89, respectively, and when the latching element 62 is biased against themounting piece 61 these apertures are in alignment with each other. Theapertures 88 and 89 are threaded and the screw 90 is threadedtherethrough. The screw 90 has a cap 91, a threaded portion 92, and areduced neck portion 94. The screw 90 is threaded through the aperture88 of the adjusting flange 68 until the reduced neck portion is locatedin the vicinity of the aperture 88, whereupon the screw is loosely heldby the adjusting flange 68. The screw 90 is then threaded through theaperture 89 of the adjusting flange 75. As is shown in FIGS. 5 and 6,when the screw 90 is initially threaded into the aperture 89 of theadjusting flange 75, the adjusting flanges 68 and 75 are held apart asubstantial distance so that the pin 80 extends through the lowerportion of the elongated aperture 78 and the latching element 62 is inits upward position. When the screw 90 is further rotated, the adjustingflange 75 of the latching element 62 will be moved downwardly thereof sothat the adjusting flange 75 is brought closer to the adjusting flange68, and the latching element 62 gradually approaches its downwardposition. Of course, the wing pieces 74 also move in a similar manner.The latching element 62 will move the distance as limited by thedimensions of the elongated hole 78.

OPERATION When the lighting fixture is to be mounted into an acousticaltile cei ling, the junction box assembly is connected to the wiring ofthe building, between the acoustical tile ceiling and the originalceiling of the building, connected to the mounting frame 11 by slidingthe connecting piece 41 thereof through the aperture 42 and into theslots 44 of the mounting piece, the mounting piece and the junction boxinserted through the hole left by a missing piece of acoustical tile inthe ceiling, and the hanger bars 16 spread so that they extend beyondthe limits of the mounting frame and will rest on the inside surface ofadjacent acoustical tile. Of course, the hanger bars are constructed sothat they are attachable to various types of installations, as bystapling, nailing, wiring, etc. After the mounting frame has been placedin position the reflector 14 is inserted through the mounting frame sothat the main body portion 45 of the reflector extends through themounting frame, as shown in FIG. 2. As the main body portion 45 of thereflector 14 passes through the mounting frame 11, the serrated wingpieces 74 of the latch 60 engage the inwardly-projecting rim 17 of themounting frame. Since the latching element 62 of the latch 60 is springbiased outwardly of the reflector by the spring 85, further movement ofthe reflector 14 in wardly of the mounting frame 11 causes the latchingelement 62 to retract inwardly of the reflector 14 and the serrations ofthe wing pieces engage the inwardly projecting rim 17 of the mountingframe 11. Of course, as the reflector 14 is further moved inwardly ofthe mounting frame 11 subsequent ones of the teeth of the wing pieces 74engage the inwardly-projecting rim 17 of the mounting frame 11, untilthe outwardly-extending flange 50 of the reflector 14 is adjacent theceiling, as shown in FIG. 2. Of course, it is diflicult to place theoutwardly extending flange 50 exactly adjacent the acoustical tileceiling in this manner since there is some play between the elements ofthe lighting fixture. In other words, in the majority of instances onlya loose fit can be attained in this manner.

Subsequent to inserting the reflector 14 through the mounting frame 11,the screws 90 of the latches 60 are rotated so that they draw thelatching element 62 downwardly on the mounting .piece 61. Of course,these serrated wing pieces 74 :move downwardly with the lacthing element62 so that the latching element 62, by way of its serrated wing pieces74, draws the inwardly projecting rim 17 of the mounting frame closer tothe outwardly extending flange 50 of the reflector 14. Therefore, whileonly a loose fit might have been attained by inserting the reflector 14through the mounting frame 11, rotation of the screws 90 of the latches60 tightens the assembly as it is mounted in the acoustical tile ceilingso that there are no gaps between the outwardly extending flange 50 ofthe reflector and the surface of the acoustical tile ceiling. Also, themounting frame 11 is drawn uniformly toward the outwardly extendingflange 50 of the reflector 14 so that the pieces of acoustical tilesurrounding the lighting fixture become compressed and aligned with eachother as the mounting frame and reflector are drawn toward each other.

As is best shown in FIG. 5 of the drawing, it can beseen that when thelatching element 62 is in its upward position a person can wedge hisfinger over the finger catch 76 and pull the latching element 62 awayfrom the mounting piece 61, against the bias of spring in a manner thattends to pivot the latching element about reduced neck portion 94 of thescrew 90. Furthermore, the spring 85 biases the washer 86 against thelower portion of the elongated aperture 78 of the latching element 62 sothat the force exerted on the latching element that urges it toward themounting piece 61 is displaced, to some degree, from the finger catch 76. This displacement creates a lever arm between the finger latch 76 andthe spring 85, the fulcrum of the lever being at the reduced neckportion 94 of the :screw 90. This amount of lever arm enables a personto move the latching element 62 in the direction as indicated by thearrow 95, thereby withdrawing the wing pieces 74 of the latching elementfrom the slot created between the mounting piece 61 and the sides of theapertures 69 in the reflector 14. Of course. this allows the personinstalling the reflector to remove it from the mounting frame 11 in casesome adjustment is needed after the reflector has been installed.

After the reflector has been installed and it is desired to finish theinstallation of the fixture, the screws 90 are rotated so that thelatching elements 62 are drawn to the position shown in FIG. 6. Ofcourse the finger catch 76 is drawn closer to the spring 85 so that thedisplacement therebetween is much shorter than that shown in FIG. 5.Furthermore, the upper portion of the elongated aperture 78 of thelatching element 62 is drawn tightly down onto the upper surface of thepin 80 so that these elements are wedged together. Of course, it ispossible that the wing pieces 74 will have drawn the mounting frame 11and the outwardly extending flange 50 of the reflector close togetherbefore the upper portion of the elongated slots 78 reaches the pin 80.In either case, however, the screw 90 will urge the adjusting flanges 68and 75 of the mounting piece 61 and latching element 62, respectively,toward each other so that the cap 91 of the screw 90 is urged toward theadjusting flange 68 of the mounting piece 61. With cap 91 of the screw90 in this condition, and with the finger catch 76 being disposedclosely adjacent the spring 85, it will be noted that the movement ofthe latching element 62 in the direction as indicated by the arrow 95will cause the latching element 62 to pivot about the edge of the cap 91of the screw 90, as opposed to the reduced neck portion 94 as shown inFIG. 5, and the force of the spring 85 must be overcome with a shorterlever arm. In other words, it i much more diflicult to move the latchingelement 62 inwardly of the reflector 14 when the latching element 62 isin its downward position than when it is in its upward position. Thiscondition, of course, insures that the latching elements 62 will not beinadvertently displaced away from the mounting piece 61, and inwardly ofthe reflector 14, after it has been installed in the ceiling. This firmmounting allows the person installing the lighting fixture to makewhatever adjustments he might desire without fear of jarring thereflector from the mounting frame 11.

After the reflector, mounting frame and junction box have been assembledin this manner, a conventional light bulb 96 is threaded into the lightsocket 22, the door 15 connected to the reflector 14 by inserting theT-shaped tabs 58 into the T-shaped apertures 51 of the reflector 14, andthen the door 15 is pivoted into place and held by the bendable tab (notshown).

While the self locking latch has been shown as connecting the reflectorof a lighting fixture to its mounting means in the ceiling of anacoustical tile ceiling, it should be understood that the latch findsvarious other uses. For instance, the latch can be utilized with airducting of a building such as the heating or air conditioning airducting. In this occasion the ducting can be installed in the walls,floors or ceilings of the building, the building substantially finishedby constructing the floors, walls and ceilings thereof, and eventuallythe grill of the ducting can be put into proper position in a mannersimilar to placing the reflector of a light fixture in its position. Ofcourse, since the latch hold the exposed piece firmly against themounting frame, be it a light fixture or air conditioning ducting, thelatch is useful in installing fixtures into the wall or floor of abuilding, and is not limited to being used only with the ceilingfixtures of a building.

Furthermore, while the latch has been disclosed as being used with anacoustical tile ceiling, it should be understood that it can be usedwith any type ceiling having a small space into which the mounting framecan be installed. In other words, only a hole in the wall or ceiling,etc., approximately the size of the mounting frame is necessary,regardless of whether it is created by the missing piece of acoustictile in an acoustic tile ceiling, or whether it is cut through a solidsurface.

It should be further pointed out that when the latch is utilized with alighting fixture only a very small portion, if any, of the lightemanating from the bulb of the fixture is lost due to the presence ofthe latch. As is shown in the drawing, the latch substantially fills thewhole area of the aperture 69 of the reflector 14 so that the light thatmight pass through the aperture 69 is reflected back to the interior ofthe reflector 14. Of course, this feature is also desirable in the useof heating or air-conditioning since a minimum amount of air, if any, islost due to the presence of the latch.

Of course, while the latch has been shown with a square fixture, itshould be understood that it can be used with other shaped fixtures,such as round, or rectangular fixtures.

At this point it can be seen that the self locking latch enables aworkman to install the lighting fixture with a minimum amount of time,using a minimum amount of skill, and in every instance of installationthe reflector can be perfectly aligned with the ceiling, or othersupporting surroundings. Furthermore, the simplicity of constructionprovides a latch that is economical to manufacture, and will firmlysupport the element to be mounted into the mounting frame.

It will be obvious to those skilled in the art that many variations maybe made in the embodiments chosen for the purpose of illustrating thepresent invention without departing from the scope thereof as defined bythe appended claims.

What is claimed as invention is:

1. A lighting fixture comprising, in combination, a mounting framehaving a vertically disposed continuous side wall and a rim extendinghorizontally inwardly from an upper portion of said side wall, areflector having a main body received within said frame with exteriorbody portions in proximate, spaced relationship with the inner perimeterof said side wall and said rim, a latching element mounted on a side ofsaid reflector for limited movement between an extended position and awithdrawn position, said latching element having a wing portionextending generally perpendicular to the side and lockably engaged withsaid rim, and means biasing said latching element in a direction tomaintain locked engagement between said wing portion and said rim.

2. A lighting fixture as claimed in claim 1 wherein said rim iscontinuous around said continuous side wall.

3. A lighting fixture as claimed in claim 1, including,

means for moving said latching element in a predetermined directionparallel to the side of said reflector, whereby, when said latchingelement is lockably engaged with said rim, movement of said latchingelement in the predetermined direction draws said reflector into saidframe.

4. A latching mechanism comprising: a mounting piece for attachment tothe exterior portion of a fixture, said mounting piece having arectangular base portion, a latching element pinned to said mountingpiece for limited movement toward and away from said mounting piece andfor limited movement in a plane generally parallel to said mountingpiece, said latching element having a substantially flat rectangularbody portion, and a pair of wing pieces disposed generally perpendicularto and extending from the sides of said body portion and around saidmounting piece, a spring biasing said latching element into contact withsaid mounting piece, an apertured adjusting flange disposedperpendicular to said base portion and extending from said base portion,and screw means extending through said apertured adjusting flange andthreadably engaged with said latching element for moving said latchingelement parallel to said mounting piece.

5. A latching device for holding a fixture within a mounting frame, saiddevice comprising, a substantially flat latching element mounted on aninterior side of said fixture for limited movement perpendicular to theside, spring means biasing said latching element against the side, saidlatching element having a wing portion extending substantiallyperpendicular to and through an opening in the side, said wing portionhaving a saw-toothed edge for lockably engaging said mounting frame, andmeans operable when said saw-toothed edge is lockably engaged with themounting frame for moving said latching element in a predetermineddirection along the side to pull the fixture into the mounting frame.

6. A latching device for holding a fixture within a mounting frame, asclaimed in claim 5, wherein said latching element has at least two wingportions extending substantially perpendicular to and through the side,each of said wing portions having a saw-toothed edge for lockablyengaging said mounting frame.

References Cited UNITED STATES PATENTS 2,965,747 12/1960 Secofsky 2401.33,189,740 6/1965 Wince 240--78 768,177 8/ 1904 Hettinger 292-641,792,292 2/ 1931 Flaherty. 3,091,687 5/ 1963 Papsdorf. 3,294,967 12/1966 Pascucci 240-78 FOREIGN PATENTS 230,619 9/ 1960 Australia.

NORTON ANSHER, Primary Examiner.

M. H. HAYES, Assistant Examiner.

US. Cl. X.R. 292-64, 68

UNITEIj STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,420,995 January 7, 1969 Bruce Patten Dunckel It is certified thaterror appears in the above identified patent and that said LettersPatent are hereby corrected as shown below:

In the heading to the printed specification, line 4, "Atlanta" shouldread Conyers Signed and sealed this 6th day of October 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, JR.

